This invention relates to a process and apparatus for air conditioning and/or heating of buildings, in particular apartment buildings.
Apparatus able to permit air conditioning and heating of buildings are of four types, being differentiated by the source of external energy, air or water, used, and by the fluid, air or water, used to restore this energy into the buildings.
The first type of apparatus comprises air/water systems generally comprised of a central installation made up of a exterior unit installed on the terrace, and ventilator-convectors arranged in the apartments to be heated and cooled, and fed from the exterior unit by means of insulated fluid conduits.
Other than their high price, such installations have several drawbacks. In the first place, they impose a certain pre-installation of the apparatus without determining whether the occupants do or do not desire the air conditioning option. Moreover, they require the installation of an energy metering system responding to specific standards, the cost of which has become relatively high. Further, such installations present a problem of flexibility when, in mid-season, certain well exposed locations require being cooled, while others locations require being heated. It will be noted that this latter problem may be resolved by installing two external units, one per face, south and north. However, this solution leads to a not inconsequential excess investment cost. Finally, all failures of the exterior group have as a consequence to cause all of the apartments in the building to go without the heating or air conditioning.
The second type of apparatus comprises water/air systems made up of heat pumps arranged in the buildings, and fed by means of a loop of constant temperature water, maintained at the desired temperature by a heater for the loop and a cooling tower serving for the evaporation of 15% of the water of the circuit for cooling the same.
This system permits overcoming certain of the drawbacks of the air/water systems described above. In effect, it is possible to heat or cool at the same time the different apartments in the building. Moreover, in the event of failure of one of the elements of the cooling tower, the operating failure affects only one apartment and not the entire building. On the other hand, this system also has drawbacks. In the first place, the noise level in the apartments is high because the compressors are installed inside the heat pumps which are installed in the apartments. Moreover, while the pre-installation is less costly in the case of an air/water system (less expensive cooling tower than the exterior unit of this air/water system, and non-insulated tubing) the overall cost of the installation is greater than that of the air/water systems.
The third type of apparatus comprises water/water systems made up of ventilator-convectors arranged in the apartments, and fed by means of a water loop provided with a cooling tower. Such a system may be compared to air/water systems with the additional drawback of not permitting reversal of the cycle.
Finally, the fourth type of apparatus comprises air/air systems provided by means of split systems, that is apparatus including the condenser part and the evaporator part, and comprising an exterior unit and an interior unit connected by a "Freon" conduit, the exterior unit comprising a fan, a compressor and a heat exchanger, and the interior unit comprising a fan and a heat exchanger.
Such split systems may be designed for treating the entire building. The interior unit is then connected to a network of ducts permitting distribution of the air to the different units of this building. Such a system has for an advantage being of a lower cost with respect to the three aforementioned systems. Moreover, the different units are treated in a completely independent manner. On the other hand, the cost price of the systems remains relatively high. Further, the noise level at the air return of the interior unit is high. Finally, the control of the temperature in the different units is very uncertain.
These split systems may also be used in an individual manner, by installing one apparatus per unit. This solution offers a great flexibility of use, but its cost is high.